Season Ten

LX-4

Both Clark Kent and Tess Mercer had discovered Lex Luthor's clones. After being killed by Major Zod, Tess discovered the clones while at Cadmus Labs. After she met Alexander Luthor (LX-15), Tess accidentally released LX-13. Unstable due to Lex's memories and the accelerated aging, LX-13 pinned Tess down and ignited Cadmus Labs, destroying the lab and killing most of Lex's other clones (including LX-4 and LX-6). With Chloe Sullivan's help, Clark discovered the clones after the fire. While Clark went to stop him from killing Lois Lane at Lawson's Field and blowing up the Daily Planet, LX-13 soon after died from the accelerated aging process. Meanwhile, Tess took in Alexander with the intent of being his foster mother.

While trying to keep Conner Kent (CNR) away from Lionel's clutches, Tess used the cremated remains of one of Lex's clones to convince Lionel the remains were Conner's. After having Christina Lamell tortured, Lionel discovered the remains were from one of the other clones.

Sometime later, Lionel discovered LX-Ø and then converted Lex's lab into the genetic engineering company PreClox.

While Apokolips was approaching the Earth, Lionel had his men capture Tess and took her to PreClox's lab. With the failure of his original plan to locate Conner, Lionel now planned on harvesting Tess's heart to restore Lex, but Tess escaped and shot Lionel. After crawling toward LX-Ø, Lionel sold his own soul to Darkseid in exchange for Lionel's heart to be placed into LX-Ø, completely restoring Lex.